Composition for manufacturing contact lenses

ABSTRACT

The invention provides a material for contact lenses, including a first siloxane macromer shown as formula (I): 
     
       
         
         
             
             
         
       
     
     in formula (I), R 1 , R 2  and R 3  are C 1 -C 4  alkyl groups, R 4  is C 1 -C 6  alkyl group, R 5  is C 1 -C 4  alkylene group, R 6  is —OR 7 O— or —NH—, R 7  and R 8  are C 1 -C 4  alkylene groups and m is an integer of about 1-2, n is an integer of about 4-80; a second siloxane macromer shown as formula (II): 
     
       
         
         
             
             
         
       
     
     in formula (II), R 9 , R 10  and R 11  are C 1 -C 4  alkyl groups, R 12 , R 13  and R 15  are C 1 -C 3  alkylene group, R 14  is a residue obtained by removing NCO group from an aliphatic or aromatic diisocyanate, and o is an integer of about 4-80, p is an integer of about 0-1; q is an integer of about 1-20; at least one hydrophilic monomer and an initiator.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a Divisional Application of the applicationSer. No. 15/441,252, filed Feb. 24, 2017, which is a DivisionalApplication of the application Ser. No. 14/931,865, filed Nov. 4, 2015,which claims priority to Taiwanese Application Serial Number 104119822,filed on Jun. 18, 2015, all of which are herein incorporated byreference.

BACKGROUND Technical Field

The present invention relates to a material for manufacturing contactlenses. More particularly, the present invention relates to ahydrophilic material for manufacturing contact lenses having lowmodulus, excellent water content and high oxygen permeability.

Description of Related Art

In the early years, hard contact lenses were mainly made of glass. Thesoft contact lenses were therefore developed to improve discomfort ofwearing of hard contact lenses. The soft contact lenses can beclassified into two categories, hydrogel contact lenses and siliconehydrogel contact lenses.

The hydrogel contact lenses are made from hydrogel materials, such aspoly-2-hydroxyethyl methacrylate (p-HEMA). Since the limited materialcharacteristics of hydrogel contact lenses, the oxygen permeability (Dk)thereof is only about 15 to 35.

Comparing to the hydrogel contact lenses, the silicone hydrogel contactlenses have higher oxygen permeability because they are made fromsiloxane macromer and hydrophilic monomers. Although the siloxanemacromer structure is able to provide high oxygen permeability, thehigher modulus thereof are therefore occurred at the same time, so as toinduce contact lens-induced conjunctival straining (C.L.I.C.S) ofwearers easily. Moreover, if the wearers wear the contact lenses in awrong way, the sickness of eyes may occur more easily. Therefore, anovel material for manufacturing contact lenses is highly demanded tosolve the aforementioned problems.

SUMMARY

According to aforementioned reasons, it is an object of the presentinvention to provide a novel material for manufacturing contact lenseshaving a lower modulus, excellent water content and high oxygenpermeability so that the contact lens-induced conjunctival straining(C.L.I.C.S) of wearers are not induced easily and increasing wearercomfort is obtained.

According to an aspect of the present invention, a composition formanufacturing contact lenses is provided.

The composition for manufacturing contact lenses includes a firstsiloxane macromer with the number average molecular weight of 500 to10,000, represented by the following formula (I),

wherein in formula (I), R₁, R₂ and R₃ are independently C₁-C₄ alkylgroups, R₄ is C₁-C₆ alkyl group, R₅ is C₁-C₄ alkylene group, R₆ is—OR₇O— or —NH—, R₇, R₈ are independently C₁-C₄ alkylene groups, m is aninteger of 1 to 2 and n is an integer of 4 to 80; a second siloxanemacromer with the number average molecular weight of 1,000 to 10,000,represented by the following formula (II),

wherein in formula (II), R₉, R₁₀ and R₁₁ are independently C₁-C₄ alkylgroups, R₁₂, R₁₃, R₁₅, are independently C₁-C₃alkylene groups, R₁₄ is aresidue obtained by removing NCO group from an aliphatic or aromaticdiisocyanate, o is an integer of 4 to 80, p is an integer of 0 to land qis an integer of 1 to 20; at least one hydrophilic monomer; and aninitiator.

According to another aspect of the present invention, a method formanufacturing the contact lenses is provided.

The method for manufacturing contact lenses includes the followingsteps. First, a first siloxane macromer, a second siloxane macromer, atleast one hydrophilic monomer, an initiator and a solvent are mixed toform a mixture. Then the mixture is injected into a mold of contact lensand conducted by a thermal treatment or a UV irradiating treatment toform contact lenses. Wherein the number average molecular weight of thefirst siloxane macromer represented by the following formula (I) is 500to 10,000 and the number average molecular weight of the second siloxanemacromer of the following formula (II) is 1,000 to 10,000;

In formula (I), R₁, R₂ and R₃ are independently C₁-C₄ alkyl groups, R₄is C₁-C₆ alkyl group, R₅ is C₁-C₄ alkylene group, R₆ is —OR₇O— or —NH—,R₇, R₈ are independently C₁-C₄ alkylene groups, m is an integer of 1 to2 and n is an integer of 4 to 80.

In formula (II), R₉, R₁₀ and R₁₁ are independently C₁-C₄ alkyl groups,R₁₂, R₁₃ R₁₅, are independently C₁-C₃ alkylene groups, R₁₄ is a residueobtained by removing NCO group from an aliphatic or aromaticdiisocyanate, o is an integer of 4 to 80, p is an integer of 0 to 1 andq is an integer of 1 to 20.

According to a further another aspect of the present invention, acontact lens obtained by the method mentioned above is provided.

The above and other aspects of the invention will become betterunderstood with regard to the following detailed description of thepreferred but non-limiting embodiment(s).

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the disclosed embodiments. It will be apparent,however, that one or more embodiments may be practiced without thesespecific details.

The present invention provides a composition for manufacturing contactlenses having a lower modulus, excellent water content and high oxygenpermeability.

According to an aspect of the present invention, the composition formanufacturing contact lenses includes a first siloxane macromer with thenumber average molecular weight of 500 to 10,000, represented by thefollowing formula (I):

wherein in formula (I), R₁, R₂ and R₃ are independently C₁-C₄ alkylgroups, R₄ is C₁-C₆alkyl group, R₅ is C₁-C₄ alkylene group, R₆ is —OR₇O—or —NH—, R₇, R₈ are independently C₁-C₄ alkylene groups, m is an integerof 1 to 2 and n is an integer of 4 to 80; a second siloxane macromerwith the number average molecular weight of 1,000 to 10,000, representedby the following formula (II):

wherein in formula (II), R₉, R₁₀ and R₁₁ are independently C₁-C₄ alkylgroups, R₁₂, R₁₃, R₁₅, are independently C₁-C₃alkylene groups, R₁₄ is aresidue obtained by removing NCO group from an aliphatic or aromaticdiisocyanate, o is an integer of 4 to 80, p is an integer of 0 to 1 andq is an integer of 1 to 20; at least one hydrophilic monomer and aninitiator.

In an embodiment of the present invention, the hydrophilic monomers forthe composition for manufacturing the contact lenses can be, but notlimited to, N-vinylpyrrolidone (NVP), 2-hydroxyethyl methacrylate(HEMA), N,N-dimethylacrylamide (DMA), methyl acrylic acid (MAA), acrylicacid, glycidyl methacrylate (GMA), (methyl)acrylamide,2-(N,N-dimethylamino) ethyl methacrylate (DMAEMA), vinyl acetate,2-(Dimethylamino)ethyl methacrylate, N-acrylolmorpholine (ACMO) and acombination thereof.

In an embodiment, the initiator suitably used in conventional formanufacturing contact lenses can be a thermal initiator or a photoinitiator. The suitable thermal initiator includes but not limited toazobisisoheptonitrile, 2,2′-azobis(isobutyronitrile) (AIBN),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(2-methyl-propanenitrile),2,2′-azobis(2-methyl-butanenitrile). The suitable photoinitiator, can benot limited to, such as, for example, 2-Hydroxy-2-methylpropiophenone,1-Hydroxycyclohexyl phenyl ketone, 2,2-Dimethoxy-2-phenylacetophenone,Benzoin methyl ether, 2,2′-azobis-isobutyronitrile or2,2-Diethoxyacetophenone.

In an embodiment of the present invention, the first siloxane macromerrepresented by the above formula (I) is present at an amount of 30 to 55parts by weight, the second siloxane macromer represented by the aboveformula (II) is present at an amount of 5 to 30 parts by weight, thehydrophilic polymer is present at an amount of 25 to 60 parts by weight,and the initiator is present at an amount of 0.1 to 1.0 parts by weight.

Moreover, although the second siloxane macromer represented by the aboveformula (II) has a cross-linking function, it is able to be added in thematerial for forming contact lenses of present invention together with across-linking agent at the same time.

In an embodiment of the present invention, the composition formanufacturing contact lenses further includes a cross-linking agent. Thefirst siloxane macromer represented by the above formula (I) is presentat an amount of 20 to 45 parts by weight, the second siloxane macromerrepresented by the above formula (II) is present at an amount of 3 to 30parts by weight, the hydrophilic polymer is present at an amount of 30to 55 parts by weight, the initiator is present at an amount of 0.1 to1.0 parts by weight, and the cross-linking agent is present at an amountof 0.1 to 5.0 parts by weight.

Further, the cross-linking agent is such as, for example ethylene glycoldimethacrylate (EGDMA), tetraethylene ethylene glycol dimethacrylate(TrEGDMA), triethylene ethylene glycol dimethacrylate (TEGDMA),poly(ethylene glycol) dimethacrylate, trimethylolpropane trimethacrylate(TMPTA), vinyl methacrylate, ethylenediamine dimethyl acrylamide,glycerol dimethacrylate, triallyl isocyanurate or triallyl cyanurate orthe combination thereof.

In an embodiment of the present invention, the first siloxane macromerrepresented by the above formula (I), includes a siloxane macromerrepresented by the following formula (I-1) or a siloxane macromerrepresented by the following formula (I-2):

wherein in formula (I-1), r is an integer of 4 to 80, and in formula(I-2), s is an integer of 4 to 80.

In an embodiment of the present invention, the second siloxane macromerincludes a siloxane macromer represented by the following formula (II-1)or a siloxane macromer represented by the following formula (II -2).

wherein in formula (II-1), t is an integer of 4 to 80, u is an integerof 1 to 10 and in formula (II-2), v is an integer of 4 to 80.

In an embodiment of the present invention, the composition formanufacturing contact lenses includes the first siloxane macromerrepresented by the above formula (I-1), the second siloxane macromerrepresented by the above formula (II-1), at least one hydrophilicmonomer and the initiator. In the embodiment, the hydrophilic monomer isa combination of NVP, HEMA and ACMO or a combination of NVP, HEMA, ACMOand DEAEMA.

In another embodiment of the present invention, the composition formanufacturing contact lenses includes the first siloxane macromerrepresented by the above formula (I-1), the second siloxane macromerrepresented by the above formula (II-1), at least one hydrophilicmonomer, the initiator and a cross-linking agent. In the embodiment, thehydrophilic monomer is a combination of NVP and HEMA or a combination ofNVP, HEMA and DEAEMA.

In still another embodiment of the present invention, the compositionfor manufacturing contact lenses includes the first siloxane macromerrepresented by the above formula (I-1), the second siloxane macromerrepresented by the above formula (II-2), at least one hydrophilicmonomer and the initiator. In the embodiment, the hydrophilic monomer isa combination of NVP, HEMA and ACMO or a combination of NVP, HEMA, ACMOand DEAEMA.

In further another embodiment of the present invention, the presentinvention provides a composition for manufacturing contact lensesincludes the first siloxane macromer represented by the above formula(I-2), the second siloxane macromer represented by the above formula(II-1), at least one hydrophilic monomer and the initiator. In theembodiment, the hydrophilic monomer is a combination of NVP and HEMA ora combination of NVP, HEMA and DMA.

In further another embodiment of the present invention, the presentinvention provides a composition for manufacturing contact lensesincludes the first siloxane macromer represented by the above formula(I-2), the second siloxane macromer represented by the above formula(II-2), at least one hydrophilic monomer and the initiator. In theembodiment, the hydrophilic monomer is a combination of DMA and HEMA.

In addition, the composition for manufacturing contact lenses canfurther includes but not limited to a dye and/or a UV-blocking agent.

According to another aspect of the present invention, a method formanufacturing contact lenses is provided. The contact lenses obtained bythe method have a lower modulus, excellent water content and high oxygenpermeability so that the contact lens-induced conjunctival straining(C.L.I.L.S) of wearers are not induced easily and increasing wearercomfort is obtained.

The present method can includes but not limited to the following steps.

Firstly, a first siloxane macromer represented by the following formula(I), a second siloxane macromer represented by the following formula(II), at least one hydrophilic monomer and an initiator are mixed toform a mixture. The formula (I) and the formula (II) are shown asfollows.

In formula (I), R₁, R₂ and R₃ are independently C₁-C₄ alkyl groups, C₄is C₁-C₄ alkyl group, R₅ is C₁-C₄ alkylene group, R₆ is —OR₇O— or —NH—,R₇, R₅ are independently C₁-C₄ alkylene groups, m is an integer of 1 to2 and n is an integer of 4 to 80. The number average molecular weight ofthe first siloxane macromer represented by formula (I) is 500 to 10,000.

In formula (II), R₉, R₁₀ and R₁₁ are independently C₁-C₄ alkyl groups,R₁₂, R₁₃, R₁₅ are independently C₁-C₃ alkylene groups, R₁₄ is a residueobtained by removing NCO functional group from an aliphatic or aromaticdiisocyanate, o is an integer of 4 to 80, p is an integer of 0 to 1 andq is an integer of 1 to 20. The number average molecular weight of thefirst siloxane macromer represented by formula (II) is 1,000 to 10,000.

In an embodiment of the method of the present invention, the hydrophilicmonomers include but not limited to N-vinylpyrrolidone (NVP),2-hydroxyethyl methacrylate (HEMA), N,N-dimethyacrylamide (DMA), methylacrylic acid (MAA), acrylic acid, glycidyl methacrylate (GMA),(methyl)acrylamide, 2-(N,N-dimethylamino)ethyl methacratyle (DMAEMA),vinyl acetate, 2-(Dimethylamino)ethyl methacrylate, N-acrylomorpholine(ACMO) and a combination thereof.

Besides, the initiator suitable used in conventional for manufacturingcontact lenses can be used in the composition of the present invention,can be a thermal initiator or a photo initiator. The suitable thermalinitiator includes but not limited to azobisisoheptonitrile,2,2′-azobis(isobutyronitrile) (AIBN),2,2′-azobis(2,4-dimethylvaleronitrile),2,2′-azobis(2-methyl-propanentrile),2,2′-azobis(2-methyl-butanenitrile). The suitable photo initiatorincludes but not limited to 2-Hydroxy-2-methylpropiophenone,1-hydroxycyclohexyl phenyl ketone, 2,2-Dimethoxy-2-phenylacetophenone,BenZoin methyl ether, 2,2′-azobis-isobutyronitrile or2,2-Dietyoxyacetophenone.

In an embodiment of the method of the present invention, the firstsiloxane macromer represented by the above formula (I) is present at anamount of 30 to 55 parts by weight, the second siloxane macromerrepresented by the above formula (II) is present at an amount of 5 to 30parts by weight, the hydrophilic monomer is present at an amount of 25to 60 parts by weight, and the initiator is present at an amount of 0.1to 1.0 parts by weight.

Moreover, in the step of forming mixture in the method for manufacturingcontact lenses, the mixture further includes a cross-linking agent.

In an embodiment of the method of the present invention, the firstsiloxane macromer represented by the above formula (I) is present at anamount of 20 to 45 parts by weight, the second siloxane macromerrepresented by the above formula (II) is present at an amount of 3 to 30parts by weight, the hydrophilic monomer is present at an amount of 30to 55 parts by weight, the initiator is present at an amount of 0.1 to1.0 parts by weight and the cross-linking agent is present at an amountof 0.1 to 5.0 parts by weight.

Further, the cross-linking agent includes but not limited to ethyleneglycol dimethacrylate (EGDMA), tetraethylene ethylene glycoldimethacrylate (TrEGDMA), triethylene ethylene glycol dimethacrylate(TEGDMA), poly(ethylene glycol) dimethacrylate, trimethylopropanetrimethacrylate (TMPTA), vinyl methacrylate ethylenediamine dimethylacrylamide, glycerol dimethacrylate, triallyl isocyanurate or triallylcyanurate or the combination thereof.

In an embodiment of the method of the present invention, the firstsiloxane macromer represented by the above formula (1) in the mixtureincludes a siloxane macromer represented by the following formula (I-1)or a siloxane macromer represented by the following formula (I-2):

formula (I-2), wherein in formula (I-1), r is an integer of 4 to 80, andin formula (I-2), s is an integer of 4 to 80.

In an embodiment of the method of present invention, the second siloxanemacromer represented by the above formula (II) in the mixture includes asiloxane macromer represented by the following formula (II-1) or asiloxane macromer represented by the following formula (II-2).

wherein in formula (II-1), t is an integer of 4 to 80, u is an integerof 1 to 10 and in formula (II-2), v is an integer of 4 to 80.

In an embodiment of the method of the present invention, the step offorming the mixture includes mixing the first siloxane macromerrepresented by the above formula (I-1), the second siloxane macromerrepresented by the above formula (II-1), at least one hydrophilicmonomer and the initiator. In the embodiment, the hydrophilic monomer isa combination of NVP, HEMA and ACMO or a combination of NVP, HEMA, ACMOand DEAEMA.

In another embodiment of the method of the present invention, the stepof forming the mixture includes mixing the first siloxane macromerrepresented by the above formula (I-1), the second siloxane macromerrepresented by the above formula (II-1), at least one hydrophilicmonomer, the initiator and a cross-linking agent. In the embodiment, thehydrophilic monomer is a combination of NVP and HEMA or a combination ofNVP, HEMA and DEAEMA.

In still another embodiment of the method of the present invention, thestep of forming the mixture includes mixing the first siloxane macromerrepresented by the above formula (I-1), the second siloxane macromerrepresented by the above formula (II-2), at least one hydrophilicmonomer and the initiator. In the embodiment, the hydrophilic monomer isa combination of NVP, HEMA and ACMO or a combination of NVP, HEMA, ACMOand DEAEMA.

In further embodiment of the method of the present invention, the stepof forming the mixture includes mixing the first siloxane macromerrepresented by the above formula (I-2), the second siloxane macromerrepresented by the above formula (II-1), at least one hydrophilicmonomer and the initiator. In the embodiment, the hydrophilic monomer isa combination of NVP and HEMA or a combination of NVP, HEMA and DMA.

In further another embodiment of the method of the present invention,the step of forming the mixture includes mixing the first siloxanemacromer represented by the above formula (I-2), the second siloxanemacromer represented by the above formula (II-2), at least onehydrophilic monomer and the initiator. In the embodiment, thehydrophilic monomer is a combination of DMA and HEMA.

In addition, the mixture could further includes but not limited to a dyeand/or a UV-blocking agent or other materials suitable used in the priorcontact lenses for providing specific functions.

In the method of the present invention, after forming the mixture, themixture is injected into a mold of contact lens and conducted a UVirradiation treatment or a thermal treatment to form contact lenses.

In an embodiment of the method of the present invention, the thermaltreatment is conducted at temperature in a range between about 30° C. to150° C. , and the reaction time is in a range between about 1 hour to 12hours. In another embodiment of the method of the present invention, thethermal treatment is conducted at temperature in a range between 30° C.to 70° C. for 0 hr to 2 hours, subsequently at temperature in a rangebetween 70° C. to 100° C. for 2 hours to 4 hours and then at temperaturein a range between 100° C. to 150° C. for 4 hours to 12 hours.

After forming contact lenses, the method of the present invention canfurther includes a hydration treatment. In an embodiment of the methodof the present invention, the hydration treatment includes but notlimited to the following steps.

Firstly, the contact lenses are soaked in alcohol solution, then soakedin water, and finally soaked in a buffer solution to reach equilibria.

According to a further another aspect of the present invention, acontact lens obtained by the method mentioned above is provided.

Additionally, the tensile modulus of the contact lenses according to thepresent invention is about 0.42 MPa to 0.7 Mpa. The water content of thecontact lenses is about 30% to 56%. Besides, the oxygen permeability ofthe contact lenses is more than 80, and preferably more than 166.

The present invention will be explained in further detail with referenceto the examples. However, the present invention is not limited to theseexamples.

1. Preparation of Siloxane Macromers

EXAMPLE A Preparation of the First Siloxane Macromer (I-1)

(I) The reaction scheme of the first siloxane macromer (I-1) is shown asfollow:

(II) Preparation of the First Siloxane Macromer (I-1)

20 g of monocarbinol terminated polydimethylsiloxane (Mw. is 1000,commercial code is MCR-C12, and is available from Gelest, US), 3.98 g of(2-(2-isocyanatoethyloxy) ethyl methacrylate, (commercial code is KarenzMOI-EG and is available from Showa Denko K. K., Japan), 0.025 g ofdibutyltin dilaurate as a catalyst and 40 mL of methylene chloride wereadded to a flask to form a solution, then the solution was stirred atroom temperature. After the solution was stirred at room temperature for6 hours, the resulting reaction product was washed with a large amountof water, and then dehydrated and filtered to obtain a raw product.Then, the methylene chloride was evaporated to obtain the first siloxanemacromer (I-1) (The number average molecular weight is 1200).

(III) The Properties of the First Siloxane Macromer (I-1)

The results of analysis were exhibited as follows:

IR Spectroscopy:

(i) Absorption bands derived from Si—CH₃ at 802 cm⁻¹ and 1259 cm⁻¹.

(ii) An absorption band derived from Si—O—Si at 1032 cm⁻¹ and 1100 cm⁻¹.

NMR Spectroscopy:

(i) A peak derived from Si—CH₃ is at around 0.19 ppm to 0.02 ppm.

(ii) A peak derived from amide group is at 5.56 ppm.

(iii) A peak derived from methyl protons of methacryloyl group is at1.93 ppm.

(iv) A peak of vinyl protons of methacryloyl group is at 5.56 ppm and6.11 ppm.

EXAMPLE B Preparation of the First Siloxane Macromer (I-2)

(I) The reaction scheme of the first siloxane macromer (I-2) is shown asfollow:

(II) Preparation of the First Siloxane Macromer (I-2)

20 g of monoaminopropyl terminated polydimethylsiloxane (commerical codeis MCR-A11, Mw. is 350, and is available from Gelest, US), 11.37 g of(2-(2-isocyanatoethyloxy) ethyl methacrylate, (commercial code is KarenzMOI-EG and is available from Showa Denko K.K., Japan), 0.025 g ofdibutyltin dilaurate as a catalyst and 40 mL of methylene chloride wereadded to a flask to form a solution, then the solution was stirred atroom temperature. After the solution was stirred at room temperature for4 hours, the resulting reaction product was washed with 20 ml of water,and then dehydrated and filtered to obtain a raw product. Then, themethylene chloride was evaporated to obtain the first siloxane macromer(I-2) (The number average molecular weight is 549).

(III) The Properties of the First Siloxane Macromer (I-2)

The results of analysis were exhibited as follows:

IR Spectroscopy:

(i) Absorption bands derived from Si—CH₃ at 802 cm⁻¹ and 1259 cm⁻¹.

(ii) An absorption band derived from Si—O—Si at 1032 cm⁻¹ and 1100 cm⁻¹.

NMR Spectroscopy:

(i) A peak derived from Si—CH₃ is at around 0.19 to 0.02 ppm.

(ii) A peak derived from amide group is at 5.56 ppm.

(iii) A peak derived from methyl protons of methacryloyl group is ataround 1.92 ppm.

(iv) A peak of vinyl protons of methacryloyl group is at around 5.56 ppmand 6.10 ppm.

EXAMPLE C Preparation of the Second Siloxane Macromer (II-1)

(I) The reaction scheme of the second siloxane macromer (II-1) is shownas follow:

(II) Preparation of the Second Siloxane Macromer (II-1)

8.88 g of isophorone diisocyanate, 0.0025 g of dibutyltin dilaurate asthe catalyst, and 40 mL of methylene chloride were added to a flask toform a solution, and the solution was stirred under a stream ofnitrogen. Then, 20 g of(α,ω-bis(2-hydroxyethoxypropyl)-polydimethylsiloxane (The number averagemolecular weight is 3000, commercial code is KF-6002, and is availablefrom Shin Etsu Chemical Co., Ltd.) was accurately weighed and addeddropwise to the solution over about 1 hour. After the solution reactingat room temperature for 12 hours, another 0.0025 g of dibutyltindilaurate and 14.4 g of polyethylene glycol monomethacrylate (The numberaverage molecular weight is 360) were accurately weighed and addeddropwise to the solution over about 1 hour. After the solution reactingat room temperature for another 12 hours, the resulting reaction productwas washed with a large amount of water, and then dehydrated andfiltered to obtain a raw product. Then, the methylene chloride wasevaporated to obtain the second siloxane macromer (II-1) (The numberaverage molecular weight is 4,000).

(III) The Properties of the Second Siloxane Macromer (II-1)

The results of analysis were exhibited as follows:

IR Spectroscopy:

(i) Absorption bands derived from Si—CH₃ is at 802 cm⁻¹ and 1259 ⁻¹.

(ii) An absorption band derived from Si—O—Si is at around 1032 cm⁻¹ and1100 cm⁻¹.

(iii) An absorption band derived from C═O of methacryloyl group isaround at 1720 cm⁻¹.

NMR Spectroscopy:

(i) A peak derived from Si—CH₃ is at around 0.1 ppm.

(ii) A peak of methyl protons derived from isophorone diisocyanate ataround from 0.8 ppm to 1.2 ppm.

(iii) A peak derived from methyl protons of methacryloyl group at around1.92 ppm.

(iv) A peak of vinyl protons of methacryloyl group at around 5.55 ppmand 6.11 ppm.

EXAMPLE D Preparation of the Second Siloxane Macromer (II-2)

(I) The reaction scheme of the second siloxane macromer (II-2) is shownas follow:

(II) Preparation of the Second Siloxane Macromer (II-2)

20 g of (α,ω-bis(2-hydroxyethoxypropyl)polydimethyl-siloxane (The numberaverage molecular weight is 3000, commercial code is KF-6002, and isavailable from Shin Etsu Chemial Co., Ltd.), 2 g of 2-isocyanatoethylmethacrylate, 0.025 g of dibutyltin dilaurate as a catalyst and 50 mL ofmethylene chloride were added to a flask to form a solution, then thesolution was stirred at room temperature. After the solution is stirredat room temperature for 6 hours, the resulting reaction product waswashed with a large amount of water, and then dehydrated and filtered toobtain a raw product. Then, the methylene chloride was evaporated toobtain a siloxane macromer (II-2) (The number average molecular weightis 3,300).

(III) The Properties of the Second Siloxane Macromer (II-2)

The results of analysis were exhibited as follows:

IR Spectroscopy:

(i) Absorption bands derived from Si—CH₃ at 802 cm⁻¹ and 1259 cm⁻¹.

(ii) An absorption band derived from Si—O—Si at 1032 cm⁻¹ and 1100 cm⁻¹.

NMR Spectroscopy:

(i) A peak derived from Si—CH₃ is at around 0.19 ppm to 0.02 ppm.

(ii) A peak derived from amide group is at 5.01 ppm.

(iii) A peak derived from methyl protons of methacryloyl group is ataround 1.92 ppm.

(iv) A peak of vinyl protons of methacryloyl group is at around 5.567ppm and 6.09 ppm.

2. Preparation of Contact Lenses

(1) The preparations of the contact lenses of Example 1 to Example 11are described in detail as follows and amounts of every component usedin Examples are listed in Table1. The physical properties of contactlenses are shown in Table 2.

(I) The preparation of the contact lenses of Example 1 to Example 7, andExample 10 to Example 11.

A first siloxane macromer (I-1), a first siloxane macromer (I-2), asecond siloxane macromer (II-1), a second siloxane macromer (II-2), athermal initiator, azobisisoheptonitrile (ADVN), N,N-dimethylacrylamide(DMA), N-vinylpyrrodine (NVP), 2-hydroxyethyl methacrylate (HEMA), ethylmethacrylate (DMAEMA) and N-acrylolmorpholine (ACMO) were mixed at theamounts shown in Table 1 and stirred about 1 hour.

Then, the mixtures were injected into a mold of contact lens made ofpolypropylene (PP) and heated to initiate the radical polymerizationthererof at 60° C. for 10 hours, then 80° C. for 2 hours, and 135′C for2 hours.

After the polymerization was completed, the mold was immersed in alcoholsolution for 1 hour and the resulting molded lens was taken out of themold. Then, the resulting lens was conducted a hydration treatment toobtain the contact lens with high oxygen permeability. Finally, asterilizing treatment was conducted. The steps and the conditions of thehydration treatment and the sterilizing treatment were as follows:

The steps of hydration treatment of the contact lenses

(a) The mold was immersed in 80% alcohol solution for 1 hour then theresulting molded lens was taken out of the mold.

(b) The polymer resulting molded lens was then immersed in 90% alcoholsolution for 1 hour.

(c) The alcohol-immersed contact lens was immersed in heated water at80′C for 1 hour.

(d) The contact lens was immersed in a buffer solution to obtainequilibrium for 12 hours.

The conditions of sterilizing treatment:

The conditions of sterilizing treatment: 121° C. for 30 minutes.

(2) The preparation of the contact lenses of Example 8 and Example 9.

The first siloxane macromer (I-2), the second siloxane macromer (II-1),the second siloxane macromer (II-2), the N,N-dimethylacrylamide (DMA),the N-vinylpyrrodine (NVP), the 2-hydroxyethyl methacrylate (HEMA) weremixed at the amounts shown in Table 1 and stirred about 1 hour. Then, aphotoinitiator, 2-Hydroxy-2-methylpropiophenone (trade name is Darocur1173 and is available from BASF, Germany) was added into the abovemixture. After that, the mixtures were injected into a mold of contactlens made of polypropylene (PP) and conducted a UV irradiating treatmentwith an accumulated energy of 2 to 3 mW/cm² for 1 hour.

After the polymerization was completed, the mold was immersed inisopropyl alcohol solution for 1 hour and the resulting molded lens wastaken out of the mold. Then, the resulting lens was conducted ahydration treatment to obtain the contact lens with high oxygenpermeability. Finally, a sterilizing treatment was conducted. The stepsand the conditions of the hydration treatment and he sterilizingtreatment were as the same as mentioned above.

(3) The physical properties of the contact lenses prepared from Example1 to Example 11, Comparative Example 1(O₂OPTIX, commercially availablefrom Ciba) and Comparative Example 2 (PureVision, commercially availablefrom B&L) were measured according to the following measuring method. Theresulting data were listed in the Table 2.

(a) Measurement of the water content of contact lenses

The contact lens was immersed in the phosphate buffered saline (PBS) for24 hours at 23° C. Then, the contact lens was removed therefrom and wastaken to remove all surface water. After that, the weight of contactlens was measured. Next, the contact lens was hydrated at 600W for 5minutes by microwave and after that the weight of hydrated contact lenswas measured. The water contact of contact lenses was calculated by thefollowing equation: (the weight of hydrated contact lenses−the weight ofdry contact lenses)/ the weight of hydrated contact lenses×100%.

(b) Measurement of tensile modulus and tensile strength of contactlenses

The test sample was cut from the middle area of a contact lens into asample size of 10 mm. Then, the test sample was immersed in a bufferspecified in ISO 18369-3 Section 4.7 for 2 hours. After that, the testsample was taken to remove all surface water and be conducted to measuretensile modulus and tensile strength by using an AI-3000 (available fromGotech Testing Maching Inc.) in a condition of temperature between 20±5°C. and a humidity between 55%±10%. The measurement was carried out at aconstant loading speed of 10 mm/min. In final, the tensile modulus andtensile strength were determined according to the initial gradient ofthe strain-stress curve. The unit of the tensile modulus is defined asMPa and the unit of tensile strength is defined as gram.

(c) Measurement of oxygen permeability of contact lenses

The oxygen permeability (Dk) was measured according to ISO standards18369-4:2006, 4.4.3, by using a oxygen permeability tester (201T). Theunits of oxygen permeability (Dk) is defined as 10⁻¹⁰ (mlO₂mm)/(cm² secmm Hg).

As shown in Table 2, the contact lenses according to the presentinvention have lower modulus than Comparative Examples. In the Example 1to Example 11, the tensile modulus thereof are all lower than 0.7 MPaand in Example 1 is even lower than 0.42 MPa. But the modulus ofComparative Example 1 and Comparative Example 2 are higher than 0.9 MPa.

Moreover, the water content of Example 1 to Example 11 are higher than30%, and the water content of Example 1 and Example 5 are even higherthan 50%. In addition, the oxygen permeability of Example 1 to Example11 are more than 80, especially in Example 6 and Example 7, the oxygenpermeability thereof are more than 150, but the oxygen permeability ofComparative Example 1 and Comparative Example 2 are only 75 and 84,respectively.

As a result, the novel contact lens material for manufacturing contactlenses according to the present invention could provide characteristicsof lower modulus, excellent water content and high oxygen permeability.

While the invention has been described by way of example(s) and in termsof the preferred embodiment(s), it is to be understood that theinvention is not limited thereto. On the contrary, it is intended tocover various modifications and similar arrangements and procedures, andthe scope of the appended claims therefore should be accorded thebroadest interpretation so as to encompass all such modifications andsimilar arrangements and procedures.

TABLE 1 The detailed composition of contact lenses of Examaple 1 toExample 11 Example (wt %) Composition Function 1 2 3 4 5 6 7 8 9 10 11First siloxane Siloxane 36.35 38.61 20.5 35.46 38.4 44.41 50.19 39.37macromer (I-1) macromer First siloxane 34.1 27.7 34.5 macromer (I-2)Second siloxane 3.75 5.62 18.8 11.43 7.3 25 6.2 macromer (II-1) Secondsiloxane 7.3 5.79 5.79 14.1 macromer (II-2) DMA Hydrophilic 11.45 15.410.5 DEAEMA monomer 18.61 3.1 NVP 18.62 17.21 26.3 20.5 24.4 32.61 27.8217.6 20 36.4 HEMA 11.42 12.28 6.2 9.46 4.8 11.41 13.52 15.9 16.4 1014.48 ACMO 4.25 2.45 4.5 2.1 2.1 0.31 ADNV Initiator 0.58 0.58 0.7 0.70.6 0.58 0.58 0.5 0.52 Darocur 1173 0.5 0.5 EGDMA Cross 0.67 2.5 linkingagent Hexanol Solvent 25 20 Ethanol 10 10 20 20 20 10 2

TABLE 2 The measurement results of Example 1 to Example 11 andComparative Example 1 and Comparative Example 2 Comparative ExampleExample Test item 1 2 3 4 5 6 7 8 9 10 11 1 2 Water 55.27 46.72 34.930.5 51.5 43.32 41.58 38.8 34.9 30.1 43.8 36 33 content (%) Tensile 0.420.5 0.49 0.55 0.58 0.65 0.64 0.53 0.62 0.68 0.7 1 0.93 modulus (MPa)Tensile 68.5 43.6 15 16.6 37 60 83 49 23 227 53.83 103 60 Strength (g)Oxygen 125 116.9 81 94 101 158 166 93 85 128 120.2 75 84 permeability(Dk)

What is claimed is:
 1. A composition for manufacturing contact lensescomprising: a first siloxane macromer with the number average molecularweight in a range of 500 to 10,000, represented by the following formula(I)

wherein in formula (I), R₁, R₂ and R₃ are independently C₁-C₄ alkylgroups, R₄ is C₁-C₆alkyl group, R₅ is C₁-C₄ alkylene group, R₆ is —OR₇O—or —NH—, R₇, R₈ are independently C₁-C₄ alkylene groups, m is an integerof 1 to 2 and n is an integer of 4 to 80; a second siloxane macromer,with the number average molecular weight in a range of 1,000 to 10,000,represented by the following formula (II)

wherein in formula (II), R₉, R₁₀ and R₁₁ are independently C₁-C₄ alkylgroups, R₁₂, R₁₃ R₁₅, are independently C₁-C₃alkylene groups, R₁₄ is aresidue obtained by removing NCO group from an aliphatic or aromaticdiisocyanate, o is an integer of 4 to 80, p is an integer of 0 to 1 andq is an integer of 1 to 20; at least one hydrophilic monomer; aninitiator; and a crosslinking agent; wherein the first siloxane macromerof formula (1) is present at an amount of 20 to 45 parts by weight, thesecond siloxane macromer of formula (II) is present at an amount of 3 to30 parts by weight, the hydrophilic monomer is present at an amount of30 to 55 parts by weight, the initiator is present at an amount of 0.1to 1.0 parts by weight and the crosslinking agent is present at anamount of 0.1 to 5.0 parts by weight based on the total amount of thecomposition.
 2. The composition for manufacturing contact lensesaccording to claim 1, wherein the first siloxane macromer comprises asiloxane macromer represented by the following formula (I-1) or asiloxane macromer represented by the following formula (I-2):

wherein in formula (I-1), r is an integer of 4 to 80, and in formula(I-2), s is an integer of 4 to
 80. 3. The composition for manufacturingcontact lenses according to claim 1, wherein the second siloxanemacromer comprises a siloxane macromer represented by the followingformula (II-1) or a siloxane macromer represented by the followingformula (II-2):

wherein in formula (II-1), t is an integer of 4 to 80, u is an integerof 1 to 10 and in formula (II-2), v is an integer of 4 to
 80. 4. Thecomposition for manufacturing contact lenses according to claim 1,wherein the initiator is a thermal initiator or a photo initiator. 5.The composition for manufacturing contact lenses according to claim 1,further comprising a dye and/or an UV-blocking reagent.
 6. Thecomposition for manufacturing contact lenses according to claim 1,wherein the crosslinking agent is selected from a group consisting ofethylene glycol dimethacrylate (EGDMA), triethylene ethylene glycoldimethacrylate (TEGDMA), tetraethylene ethylene glycol dimethacrylate(TrEGDMA), poly(ethylene glycol) dimethacrylate, trimethylolpropane trimethacrylate (TMPTA), vinyl methacrylate, ethylenediamine dimethylacrylamide, glycerol dimethacrylate, triallyl isocyanurate, triallylcyanurate and the combination thereof.